The primary goal of the proposed intervention is to conduct a longitudinal effectiveness trial of a multimodal, integrated preschool program designed to improve children's school readiness by promoting pre-Iiteracy, communication, mathematics and socioemotional skills in children at risk for school difficulties. The proposed intervention program consists of a variety of integrated curriculum materials and training methods including intensive teacher training workshops, individual on-site technical assistance with formalized protocols, specific math and pre-literacy classroom activities, and individual primer/booster sessions for a subgroup of aggressive children. Children living in a low-income family or community are at particularly high risk for school failure and constitute the primary target population for this application. The sample will include children attending Head Start and community child care programs. Teachers will be randomly assigned to one of three conditions: Control, Workshops Only, or Workshops Plus. Teachers in both treatment conditions will receive 30 hours of group-based teacher training. Teachers in the Workshops Plus condition will additionally receive on-site technical assistance consisting of individual consultation and mentoring. Teacher outcomes will be assessed in baseline, intervention, and maintenance years. Child assessments will be conducted in the fall and spring of the intervention year and after the children have made the transition to kindergarten. The outcomes of the proposed research will inform teachers, program directors, and policymakers as they make important decisions about the directions and expansion of early childhood efforts in the U.S.